If used in an italics environment, the superscript plus sign (⁺, U+207A) appears as Non-printable U+2064, aka invisible plus. Would it be possible to add this sign to Junicode?
It would be enough if the superscript plus sign appeared in an italics environment in its upright shape. As far as I am concerned, the sign itself doe not need to be in italics.
The numbers and operators in the range U+2070-U+208F had not been completely filled in (the Italic face is not as complete as the Regular; I usually fill things in quicker when people ask). All these things have now been added and the sups and subs lookups filled in. They'll be in the next release.